Is Flavokawain B dangerous or at least as dangerous as the media hype often claims it is?
Before we tackle this relatively simple question, let’s explore what exactly Flavokawain B (FKB for short) is. Of all the studies I’ve read, a study published on the US National Library of Medicine called “Flavokawain B, the hepatotoxic constituent from kava root, induces GSH-sensitive oxidative stress through modulation of IKK/NF-κB and MAPK signaling pathways” states the case most clearly in my opinion.
First, we need to understand there are are a number of components that make up Kava. Six that get the most press are called “Kavalactones”, because 6 of these Kavalactones are associated with the various pleasant and anxiety-reducing effects that Kava is responsible for. These 6 are known as Desmethoxyyangonin (#6), Dihydrokavain (#2), Yangonin (#3), Kavain (#4), Dihydromethysticin (#5), and Methysticin (36). As the above study explains it:
The major constituents of ethanolic kava root extract are kavalactones, including kawain, dihydrokawain, methysticin, dihydromethysticin, yangonin, and desmethoxyyangonin. Kava root extracts also contain chalcones, including flavokawain A, flavokawain B, and flavokawain C. We initially screened all 6 major kavalactones and 3 chalcones for cytotoxicity toward HepG2 hepatoma cells using MTT assays. None of the kavalactones, except yangonin, exhibited toxicity at concentrations up to 150 μM.Ping Zhou, Shimon Gross, Ji-Hua Liu, Bo-Yang Yu, Ling-Ling Feng, Jan Nolta, Vijay Sharma, David Piwnica-Worms, and Samuel X. Qiu
What we’re mostly interested in here are the three chalcones that Kava also contains, specifically the one that’s known as Flavokawain B or FKB. Interestingly enough, Kava can be categorized as Noble Root and non-Noble root. Noble root is typically associated with “pure” types of Kava root, that can be traced to a single geographical origin. For example, the Kava we carry most often is a Noble root from Vanuatu. Most often, it has a lineup of 4-2-3, and contains about 13% of Kavalactone. It’s a very smooth drinking Kava, known for it’s very pleasurable effects. (Thanks to Wonderland-Labs, a Kava testing lab.)
Conversely, there’s a non-noble variety called “Tudei” Kava. This is a fast-growing Kava that can be found in many parts of the world, and exported from various regions in Oceania to everywhere else in the world. Tudei typically grows larger, thicker roots in just one-third to two-thirds less time than Noble Kava root. It can withstand more severe conditions, and can produce more Kava per square acre than typical Noble Kava root can.
This was very important a couple of decades ago when Kava demand was rising sharply, and supply was low. Kava needs to mature for at least two years before you can take the first harvest, and really sought after Kava matures for 5 years or more. Tudei can start to be harvested before that initial two-ear period is over, further increasing the amount of Kava that can be brought into the marketplace.
One of the issues that has come to the forefront with non-noble Kava, and specifically Tudei Kava, is that it also typically contains more Flavokawain B (FKB) than Noble varieties of Kava. But how much more does it really have, and is this larger amount of FKB actually a problem when it comes to liver damage?
Let’s take a look at the numbers before we rush to any judgement.
Interestingly, all other compounds tested, including FKA and yangonin, failed to induce cell death in L-02 cells (data not shown). FKB (Fig. 1B) was therefore chosen for further investigation, not only because it was a more potent cytotoxin in liver cells as compared to FKC, but also because FKB was >20-fold more abundant than FKC in acetone or ethanol extracts of kava.
O.K., so a growing body of evidence is pointing to the fact that Kavalactones are harmless, even in extraordinarily large doses. But what about Flavokawain-B (FKB)? Not only does this study state that FKB is capable of causing cell death, they have made it the central theme of their paper. Shouldn’t we be deeply concerned?
Let’s continue reading for just a minute more, and then I’ll explain exactly why I can make a very controversial and bold statement that the hype over the dangers of FKB is extremely overblown and possibly even specific agenda-driven.
Surprisingly, all 3 chalcones induced significant cell death in HepG2 cells at concentrations ranging from 10 to 50 μM. FKB is the most potent cytotoxin, exhibiting an apparent LD50 value of 15.3 ± 0.2 μM. To confirm these findings, we next tested all 9 compounds against an immortalized nontumor origin human liver cell line, L-02. Again, FKB and FKC induced cell death in L-02 cells, with LD50 values of 32 and 70 μM, respectively.Ping Zhou, Shimon Gross, Ji-Hua Liu, Bo-Yang Yu, Ling-Ling Feng, Jan Nolta, Vijay Sharma, David Piwnica-Worms, and Samuel X. Qiu
Interpreting Those Scary FKB Numbers
Pretty scary stuff, right?
NOT when we take a closer look…
Let’s translate those seemingly numbers into numbers we all can relate to and understand. First, there are two key factors that need to be explained here:
- Most consumers extract their Kava into WATER. If you look at the chart below, you will see the amount of Flavokawain B (FKB) typically extracted into water. It shows that there is 0.2mg/g of FKB for every 46.6 grams of Kavalactone. Since a usual dose (as set out by the FDA) is 290mg per day, let’s assume you made a very strong Kava drink that contained the full 290mg of Kavalactones in them. That means that you would be consuming just 1.2mg of Flavokawain-B (FKB) for your entire daily dose!
- Any high quality Kava supplier will offer extracts that are WATER-ONLY extractions. Every single Kava product we offer here is a water-based extraction, under pressure. This produces phenomenal results, and extracts about 90% of the total Kavalactone content, with amounts of FKB comparable to the below chart.
So, let’s look closely at the amounts given to the test subjects in the above study.
Mice were orally administered an equivalent of 25mg/kg body weight of FKB daily for 1 week.
Translated into human terms, for a 125lb/57kg person that’s 1425mg of FKB every single day for a week. For a 165lb/75kg person that’s 1875mg of FKB every single day for an entire week. If we take an average, that’s 1650mg of FKB a day, every day for a week, for an average person.
This is a nearly physically impossible amount of FKB to get into any bodily system without being directly injected.
It would take a person consuming nearly 500 times a full daily serving of water-based Kava drinks every single day for a week to reach the levels that were given to the mice. That’s 500 water-based shells of Kava a day for seven days straight.
I doubt that even the most avid Kava drinker has consumed that much, and I’m not actually sure it’s very possible to consume that much. If we assume that a shell of Kava contains about 6 ounces of liquid, on top of all that Kava, an average size person would have to consume 2,750 ounces of Kava drink a day for a week. That translates into over 21 gallons of Kava drink a day, every day, for a week.
Anyone drinking 21 gallons of anything a day is likely to do some sort of bodily harm to oneself.
This isn’t to say that less Kava a day couldn’t be harmful to the liver. But many studies don’t work with real-world doses of Kava.
Why Report Non-Real-World Numbers?
What this means for nearly all Kava consumers is clear:
There is little to no evidence that Kava is hepatotoxic in the amounts a typical (or even a non-typical) Kava consumer would ingest over a day, week, or even years.
Even if we do a worst-case scenario, and someone purchased Kava that was made from an ethanol extraction, one would still have to consume over 100 full-serving shells of Kava in a day to achieve those same results.
The question becomes WHY these kinds of numbers are reported in the way they are, and in ways only scientists and researchers can understand. To find the answer to this question, I did some research of my own, and spoke with several researchers who had completed studies on Kava, both positive and negative. One of those people was from the quoted study above, but declined to be mentioned by name in this article.
What I did find is that the reasons I was given were relatively wide and varied. It depended if the researchers were independent or associated with an institution or business such as a pharmaceutical company.
But something that did come up repeatedly is that researchers need to find definitive results. I was told that one needs to go to the extreme to find the limits, in this case, of toxicity. Researchers are looking for that all-important “LD“ number. LD stands for “lethal dose,” and refers to an amount that will kill 50% of any exposed population. So, as in the study quoted above, researchers were looking for LD50/7, which translates into what the required dosage was to kill 50% of the mice in 7 days. A study won’t have a great deal of merit if the lethal dose isn’t found, even if there is no lethal dose (such as cannabis, which has no lethal dose).
Caffeine Lethal Dose
What seems to get lost in translation and in media hype is this critical detail. If we simply look at the headlines “FKB is a potent hepatotoxin,” we miss the real-world application and results of this study, as well as the context. Just about anything in extraordinarily large doses can be lethal. For example, let’s take caffeine:
When Jack James (editor-in-chief of the Journal of Caffeine Research) was asked about whether or not there is a lethal dose for caffeine, he told me that on average, adults needs 10000mg of caffeine at once to die from it. Since most people typically ingest about 2mg/kg of caffeine per caffeinated drink, or about 5mg/kg of caffeine per typical coffee drink, this is an extraordinarily large number. When we first look at the headlines about “caffeine toxicity”, it can be more than a little scary. But, if we put it into context, a person would typically have to drink about 16 gallons of coffee at once to die from it.Jack James
The Health Benefits of Tudei Kava
So, context truly is everything. When we take a clear, objective look at whether or not 2-5-3 Kavalactone kava (typically Tudei Kava) which often contains higher levels of Flavokawain B than other varieties of Kava, are we really endangering our health? Apologists would say that anything that has even a chance of causing harm to our bodies isn’t worth the risk. But, I would find it difficult to believe that those same people didn’t ever consume caffeine, or alcohol, or consume large amounts of sugar in a day, all of which can contribute to the #1 killer in the United States; heart disease.
Furthermore, there is a peer reviewed study on Flavokawains that came out in January of 2016 that disputes those claims outright. This study has concluded that the amounts of Flavokawain B (FKB) contained in the amounts of Kava an average consumer might typically ingest, are not harmful, but protective to our health. Some may find this difficult to believe, but the evidence is vividly clear:
Flavokawains promote an adaptive cellular response that protects hepatocytes against oxidative stress. We propose that FKA has potential as a chemopreventative or chemotherapeutic agent.
Both flavokawains activated Nrf2, increasing HMOX1 and GCLC expression and enhancing total glutathione levels over 2-fold (p < 0.05).
Calculations by Teschke et al. have shown that the dose of FKB obtained from an ethanolic kava extract is 250-fold below the amount needed to cause modest hepatotoxicity, based on rodent studies (Teschke et al. 2011).
I agree that more studies need to be done in regards to the toxicity of Flavokawain B (FKB), and that there is evidence that it can be harmful in extraordinarily large doses. But in real world consumption, whether it’s Noble Kava root from Vanuatu, or Tudei Kava from somewhere else, the truth vastly less alarming than what many have led us all to believe. We have more than a few Kava lovers who swear by their Tudei Kava. One person says:
Tudei kava root (2-5-3 lineup) is very popular in the USA with kava our drinking clients. They say that it gives them a very clean and pleasant effect, and wake up with no hangover, but a freshness the next morning. Please don’t let the “Tudei Kava” literature and talk mislead you. You will never regret using this Kava, and it’s only about one-third the cost of other varieties at the moment.
So, decide for yourself. Some people think tudei Kava is the scourge of the Kava world, while others swear by it. Do your own research, try out some noble root, try out some Tudei Kava, and decide for yourself.
Everyone here, and numerous families we have known throughout the generations have enjoyed Kava on a daily basis for most of their lives. For many, they can’t imagine a day without their coffee or their Starbucks. I, and many people I know, can’t imagine a day without Kava. Because my health is so important to me, I get blood work on a regular basis, partly to prove to myself that the copious amounts of Kava that I consume aren’t, in fact, damaging me.
Time after time, test after test, my liver shows normal. I rarely get any increased enzyme levels, and one one occasion, I even went to the doctor in the late afternoon, after consuming a couple of shells of Kava at lunch, just out of curiosity. I was completely normal.